Mexican authorities announced they will begin the process of extraditing drug kingpin Joaquin "El Chapo" Guzman to the United States, as his lawyer vowed a tough legal battle.
President Enrique Pena Nieto's government had balked at extraditing Guzman prior to his prison break in July but the administration has changed tack after recapturing him on Friday.
The attorney general's office said it received two US extradition requests last year on a slew of charges, including drug trafficking and murder, and that it later obtained arrest warrants to ship him across the border.
"With Guzman Loera's recapture, the respective extradition proceedings will have to start," the office said in a statement, though it did not indicate when the hearings would start.
Lawyers for Guzman will have three days to file objections and 20 more days to prove them, though that timeframe can be extended, prosecutors said, vowing to fight any appeals.
Once a judge rules on the extradition, the decision is sent to the foreign ministry, which will have 20 days to validate it. Guzman would have another chance after that to legally challenge the decision.
One of Guzman's attorneys, Juan Pablo Badillo, vowed to take the case up to the Supreme Court if necessary.
"A legal battle has begun in the constitutional framework that will be very serious, very tough," Badillo told reporters outside the Altiplano prison near Mexico City, where Guzman was sent following his arrest on Friday.
"He shouldn't be extradited because Mexico has a fair Constitution," he said.
US President Barack Obama's administration congratulated Mexico following the arrest but did not publicly indicate whether it would press Pena Nieto to extradite Guzman.
US politicians called for his immediate extradition as he faces charges in a half-dozen states.
Some questioned Mexico's ability to hold on to a man who fled prison through a tunnel under his cell's shower in July and fled from another penitentiary in a laundry cart in 2001.
"Given that 'El Chapo' has already escaped from Mexican prison twice, this third opportunity to bring him to justice cannot be squandered," said US senator and Republican presidential hopeful Marco Rubio.
A Mexican federal official defended the decision to send Guzman back to Altiplano, saying measures were taken to improve security, including the installation of metal rods under the floor of prison cells.
- Biopic bid -
The world's most wanted drug baron was arrested after a deadly military raid early Friday in Los Mochis, a coastal city in his native northwestern state of Sinaloa.
Hours later, the Sinaloa cartel kingpin was flown to the Altiplano maximum-security prison, some 90 kilometers (55 miles) west of the capital.
On July 11, after just 17 months at Altiplano, Guzman slipped through a hole in his cell's shower, climbed on a motorcycle mounted on rails, and traveled 1.5 kilometers (one mile) through a tunnel to freedom.
But six months later, Guzman was back in custody after authorities located him, thanks to the kingpin's bid to make a biographical film about himself, according to Attorney General Arely Gomez.
Gomez said Guzman even "established contact with actresses and producers" through his attorneys.
- Last escape -
The months-long manhunt culminated in a house in the palm tree-lined city of Los Mochis, which authorities began to stake out in December after pursuing him across the mountains of Sinaloa.
Marines were met by gunfire when they swooped in on Friday, leaving five suspects dead and one marine wounded. Six others were detained in the operation
"When we had the courage, we looked out the window and saw the soldiers on the ground firing at the garage door until they opened it," said a neighbor.
Guzman and his security chief fled through the city's drainage system, repeating a tactic the drug kingpin successfully used in escaping authorities in 2014 in the nearby city of Culiacan. This time however the marines expected such a move, Gomez said.
The wanted men came out of a manhole and stole a car, but they were captured on a road and taken to a motel, where Guzman was seated on a bed, wearing a dirty sleeveless shirt -- an ignominious end for a kingpin whose billionaire drug business reaches as far as Asia and Europe.